template/All Cycle Path.cpp at main · sazid62/template · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(), x.end()
#define pb push_back
#define endl '\n';

const int N  = 1e6;
vector<int> graph[N];
vector<vector<int>> cycles;

int color[N];
int par[N];


void dfs_cycle(int u, int p, int color[], int par[], int& cyclenumber)
{


    if (color[u] == 2) {
        return;
    }


    if (color[u] == 1) {
        vector<int> v;
        cyclenumber++;

        int cur = p;
        v.push_back(cur);


        while (cur != u) {
            cur = par[cur];
            v.push_back(cur);
        }
        cycles.push_back(v);
        return;
    }
    par[u] = p;

    color[u] = 1;

    for (int v : graph[u]) {


        if (v == par[u]) {
            continue;
        }
        dfs_cycle(v, u, color, par, cyclenumber);
    }


    color[u] = 2;
}

void solve() {
    int cyclenumber = 0;
    dfs_cycle(1, 0, color, par, cyclenumber);
}


int32_t main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int t = 1;

    // cin >> t;
    while (t--)
        solve();
    return 0;
}